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Metal-oxide-semiconductor field-effect transistor with a vacuum channel
Siwapon Srisonphan1, Yun Suk Jung, Hong Koo Kim
1Department of Electrical and Computer Engineering and Petersen Institute of NanoScience and Engineering, 1140 Benedum, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
Nature Nanotechnology
|July 4, 2012
Summary
Researchers developed a novel low-voltage transistor using a vertical vacuum channel. This design enables high-speed electron transport, overcoming scattering limitations in solid-state devices for efficient electronics.
Area of Science:
- Solid-state physics
- Materials science
- Nanoelectronics
Background:
- High-speed electronics require short carrier transport times, ideally ballistic transport.
- Achieving ballistic transport in solids is challenging due to scattering at high electric fields.
- Vacuum offers ideal ballistic transport but faces issues with low currents and high voltages.
Purpose of the Study:
- To fabricate a low-voltage field-effect transistor with a vertical vacuum channel.
- To investigate the potential of two-dimensional electron systems for high-current emission into vacuum.
- To enable a new class of low-power, high-speed transistors.
Main Methods:
- Fabrication of a transistor with a ~20 nm vertical vacuum channel in a metal-oxide-semiconductor substrate.
- Measurement of device performance including transconductance, on/off ratio, and turn-on gate voltage.
- Analysis of Coulombic repulsion effects on electron emission from a two-dimensional electron system.
Main Results:
- Achieved a transconductance of 20 nS µm(-1) and an on/off ratio of 500.
- Demonstrated a low turn-on gate voltage of 0.5 V under ambient conditions.
- Obtained high emission current density (~1 × 10(5) A cm(-2)) at a low bias of 1 V due to reduced energy barriers.
Conclusions:
- The novel transistor design effectively utilizes vacuum channels for high-speed transport.
- Coulombic repulsion facilitates efficient electron emission from 2D systems, enabling high currents.
- This approach paves the way for developing next-generation low-power, high-speed electronic devices.
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